A REVIEW OF RECENT INVESTIGATIONS ON THE 

 MINERAL NUTRITION OF FUNGI 



ARTHUR W. DOX 

 (Chemical Seciion of the Iowa Agricultural Experiment Station, Arnes, Iowa) 



Pasteur^ appears to have been the first to make use of a syn- 

 thetic culture medium for the propagation of lower fungi, and to 

 recognize the importance of mineral mitrients. By means of iuch 

 a medium he succeeded in demonstrating the dififerential rate of 

 destruction of the two isomers of a racemic mixture through the 

 action of a common mold. A decade later RauHn^ proposed a 

 synthetic medium especially adapted to the common black mold, 

 Aspergillus niger, with which he carried out his investigations. 

 RauHn's medium is to this day perhaps the best known and most 

 widely used for the cultivation of this and similar organisms. In 

 addition to sucrose and tartaric acid, which supply the necessary 

 carbon, and ammonium nitrate, which furnishes the nitrogen, it 

 contains the f ollowing mineral elements : phosphorus, sulphur, po- 

 tassium, magnesium, zinc, iron and silicon. Raulin showed that 

 the Omission of one or more of these elements resulted in a retarda- 

 tion of growth and a decreased yield of the fungus. 



By far the greater number of subsequent investigations on the 

 mineral nutrition of fungi have been carried out with this same 

 organism, Aspergillus niger. When this fungus is grown upon 

 Raulin's medium at its Optimum temperature, 35° C, germination 

 occurs during the first twenty-four hours, the surface of the liquid 

 soon becomes covered with a white mycelium, and about the fourth 

 day black spores appear and the surface of the culture becomes jet 

 black. At room temperature the growth is somewhat slower, the 

 spores making their appearance in about a week. The investigations 

 reviewed below are concerned for the most part with this character- 

 istic organism. 



^Pasteur: Compt. rend., 51, 298-g (1860). 

 2Rau!in: Ann. Sei. Nat. (Bot.), u, 93-299 (1869). 



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